1. Field of the Invention
The present invention relates to a liquid-droplet jetting apparatus which jets a droplet of a liquid (liquid droplet) from a jetting port (discharge port).
2. Description of the Related Art
In an ink-jet head (liquid-droplet jetting apparatus) which jets an ink from nozzles by applying a pressure to the ink in pressure chambers, when the pressure is applied to the ink in a certain pressure chamber among the pressure chambers, a pressure wave is generated in the certain pressure chamber. When the pressure wave generated in the certain pressure chamber is propagated to another pressure chamber via a common liquid chamber which communicates with the pressure chambers, the jetting characteristics of the ink (ink-jetting characteristics) become non-uniform. Considering this situation, there has been hitherto known a technique for attenuating the pressure wave in the common liquid chamber to prevent the pressure wave generated in a certain pressure chamber from being propagated to another pressure chamber, thereby suppressing the ink-jetting characteristics from becoming non-uniform. For example, in an ink-jet recording head (ink-jet head) described in Japanese Patent Application Laid-open No. 2003-127354, a plurality of pressure generating chambers (pressure chambers) communicating with nozzles respectively communicate with an ink storage chamber (common liquid chamber) via an ink supply channel. A recess is formed in a head case at a portion thereof corresponding to the ink storage chamber, and a portion, of a vibration plate, which overlaps with the recess, functions as a damper which relieves a pressure fluctuation (attenuates the pressure wave) in the ink storage chamber.
However, in the ink-jet head described in Japanese Patent Application Laid-open No. 2003-127354, when an attempt is made to realize the densification and miniaturization of the ink-jet head, the common liquid chamber also becomes small in size. Therefore, it is not possible to form a recess having a sufficient size for attenuating the pressure wave, and thus the area dimension of the portion, of the vibration plate, which functions as the damper becomes small. Consequently, there is a fear that the pressure wave cannot be attenuated sufficiently in the common liquid chamber.